Various types of biometric systems are used more and more in order to provide increased security and/or enhanced user convenience. In particular, fingerprint sensing systems have been adopted in, for example, consumer electronic devices, thanks to their small form factor, high performance, and user acceptance.
Among the various available fingerprint sensing principles (such as capacitive, optical, thermal etc.), capacitive sensing is most commonly used, in particular in applications where size and power consumption are important issues. All capacitive fingerprint sensors provide a measure indicative of the capacitance between each of several sensing structures and a finger placed on or moved across the surface of the fingerprint sensor.
Moreover, fingerprint sensor integration in smart cards is increasingly requested by the market. However, the requirements of the fingerprint sensor in a smart card may change compared to when the sensor is used in a smartphone. For example, since the cost of a smartcard is significantly lower than the cost of smartphone, it is even more desirable to reduce the cost of the fingerprint sensor for a smart card.
In presently available smart cards, fingerprint sensor modules can be soldered on an inlay and the card is in turn laminated with the inlay as a center layer and with a cavity in the card upper layer leaving the fingerprint sensor module exposed upon card lamination.
However, a gap between the fingerprint sensor module and the card body is often visible, creating reliability and cosmetic problems. Moreover, the described process is typically only used for limited series and not suitable for mass production.
Accordingly there is a need for an improved method for providing a smartcard comprising a fingerprint sensor module, and for a fingerprint sensor module for integration in a smart card.